Internal combustion engine



July 3, 1934. A. L, HART INTERNAL COMBUSTION ENGINE Filed'Dec. 22. 1950 2 Sheets-Sheet 1 gwuentoc Fl. L- HFIRT dttozmq July 3, 1934. A. HART INTERNAL COMBUSTION ENGINE Filed Dec. 22. 1930 2 Sheets-Sheet 2 L14 7 gnuenloc Fl- L- Ham" Patented July 3, 1934 UNITED STATES PATENT OFFICE 1,965,548 INTERNAL COMBUSTION ENGINE Alvin L. Hart, San Diego, Calif.

Application December 22, 1930, Serial No. 503,909 Claims. (c1. 12340) The principal object of my invention is to provide an internal combustion motor of great power and an exceptionally wide and flexible speed range.

A further object of my invention is to provide a motor that develops and delivers uniform unintermittent power.

A still further object of my invention is to provide an internal combustion engine that gives an increased number of explosive impulses to the engine shaft during one complete revolution of the shaft.

A still further object of my invention is to provide an internal combustion motor that will rotate itsengine shaft either to the right or to the left at will, merely by greatly advancing or greatly retarding the ignition spark.

A still further object of my invention is to provide a combustion engine that has a'favorable leverage on the engine shaft at and during the time of the explosion impulse.

A still further object of my motor is to provide a favorable leverage on the compression stroke of the compression piston.

A still further object of my invention is to provide an internal combustion motor that is economical in manufacture and durable in use,

These and other objects will be apparent to those skilled in the art.

My invention consists in the construction, arrangernent and combination of the various parts of the device, whereby the objects contemplated are attained as hereinafter more fully set forth, pointed out in my claims and illustrated in the accompanying drawings, in which:

Fig. 1 is a side View of my engine with a portion of its crank case and parts cut away.

Fig. 2 is a front sectional view of my invention taken on line 22 of Fig. 1, with the bar connecting toggles removed and more fully illustrates its interior construction.

Fig. 3 is a side view of the two spaced apart cams on the engine shaft.

Fig. 4 is a front view of the two cams and shows their relations one to the other. i

Fig. 5 is a side view of the means for operatively connecting the bars on each supportin shaft together.

Fig. 6 is a top plan view of one pair of hinged bars supporting a camengaging caster.

In the drawings I show my invention as applied in a radial type motor particularly adaptable to air craft.

However, the invention may be applied to the cylinder in line, 'V-type or opposed type engines.

I have used the numeral 10 to designate the cylindrical crank case of my motor, having the engine shaft 11 rotatably journaled therein. Inside this case 10, rigidly securedon the shaft 11 and spaced apart are the two cams 12 and 13. Each of these cams have three circular depres sions 14, 15 and 16 in their peripheries, thereby providing three radially extending projections 17, 18 and 19. These projections are equally spaced apart and are rounded as shown in Fig. 4. The numerals 20 and 21 designate two slightly spaced apart compression cylinders located in a line parallel with the engine shaft. Any number of pairs of such cylinders may be used, depending on the number of cams. In the drawings I show four pairs, secured radially to the crank case and equally spaced apart one from the other. To the side of and adjacent each compression cylinder 20 is an explosion cylinder 22 and to the side of and adjacent each compression cylinder 21 is an explosion cylinder 23. By this arrangement the explosion cylinders are also, in groups of equally spaced apart pairs and extend radially from the crank case. Securing the top of each compression cylinder to the top of the explosion cylinder adjacent to it is a bridgeor head member 24.

The numeral 25 designates the fuel inlet port of each compression cylinder designed to be in communication with a source of explosive engine fuel. Once the fuel enters the cylinder it is prevented from returning through the inlet port by the usual one-way valve and stem 26 yieldingly held in a closed position by the spring 27, as shown in Fig. 2.

The numeral 28 designates an outlet port in the top of the compression cylinder and the numeral 29 designates an inlet port in the top of the explosion cylinder adjacent thereto. The numeral 30 designates a passageway in each head 24 communicating at one end with the outletport 28 and at its other end with the inlet port 29. The port 28 is yieldingly closed by a spring actuated one-way valve 31. This valve permits gas to pass from the compression cylinder, but prevents its return. The port 29 is yieldingly closed by a spring actuated one-way valve 32, which permits the fuel gas to pass into the explosion cylinder, but prevents its returnback through the port 29. These one-way valves 26, 31, and 32 may have their upper ends that extend beyond the head 24 inclosed if desired. In the drawings, I show two of these'valves 31 and 32 inclosed by a cover member 33.

The numeral 34 designates the exhaust pipe leading from each of the explosion or combustion cylinders and is located at a point a considerable distance from the top of the same. The numeral 35 designates a spark plug threaded into each of the explosion cylinders of the motor and are designed to be in electrical communication with a suitable distributor which is in turn in electrical communication with a source of electrical energy. Rigidly secured inside the crank case 10, located near the side of the same,

and positioned to theside of each bank of cylinders is a rod 36. These four rods are equally spaced apart and are parallel with the engine shaft 11. Rotatably mounted on each of these rods 36 at their rear ends are two pairs of spaced apart arms 37 and 38 respectively. Each of these pairs of arms 37 extends to a position below a pair of cylinders 20 and 22 and the other pair of arms 38 on the same" rod extends to a position below the cylinders 21 and 23 at the side of the cylinders 20 and 22 which are above that pair of arms 37.

In'each ofthe explosion cylinders is a piston head 39. The numeral 40 designates a link having one end connected to the piston head inside each of the cylinders 22 and its other end connected to the free end of the pair of arms 37 below that cylinder. Similar links connect the pistons in the explosion cylinders 23 with the pair of arms 38 below those cylinders. The numeral 41 designates a piston head in each of the compression cylinders 20 and 21. The numeral 42 designates a link operatively connecting each of the pistons in the cylinders 21 with the pair of arms 37 below that cylinder. A similar link connects the pistons in the cylinders 21 with the pair of arms 38 below them respectively. As these links and pairs of arms are so positioned as to be approximately at rightangles to each other when the pistons in the cylinders are at their extreme downward position,.the position that the links 42 are operatively connected to the pairs of arms will be some distance from the free ends of those arms, or in other words, some distance back from the point where the links 40 are operatively secured to the free ends of the pairs of arms. 1

This is also true of the links similar to the links 40 and 42 that are secured to the-pistons inside the cylinders 21 and 23. Each pair of arms 37 and 38 curve inwardly toward the shaft 11 in between the points where the links 40 and 42 are secured to the arms. Rotatably mounted in each pair of arms at a point between the positions where the links are hingedly secured to the pair of arms is a caster 43, as shown in Figure 2. By placing the two cams 12 and 13 between the plurality of pairs of arms 37 and the engine shaft and between the plurality of pairs of arms 38 and the engine shaft 11 respectively, these casters 43 will be capable of engaging and rolling on the periphery of the two cams respectively, as shown in the drawings.

By this arrangement, the caster wheels rotatably mounted to the pairs of arms 37 will engage the periphery of the cam 12 and the casters 43 on the pairs of arms 38 will be capable of engaging the cam 13. Extending between the two pairs of arms 37 and 38 on each of the rods 36 is a bracket 44 secured by any suitable means to the crank case 10. Slidably mounted in each of these brackets 44 and positioned approximately transversely of the pairs of arms to each side of it is a bolt 45. Pivoted on the inner end of this bolt 45 is a toggle member 46. The numeral 47 designates a coil spring embracing the bolt 45, having one end engaging the bracket 44 and its other end engaging the toggle 46 for yieldingly holding the toggle 46 inwardly and away from the two pairs of arms 37 and 38 to each side of it. The

numeral 48 designates a metallic band extending around each of the toggles 46 and having its two ends pivotallysecured to the two pa rs of upwardly in their respective cylinders.

arms 37 and 38 which are positioned at each side of the bolt 45 holding that particular toggle.

As the cams 12 and 13 have their projections positioned exactly contrary to each other, as shown in Figure 4, each group of pairs of arms 37 and 38 will be moving in opposite directions when the cams are turning and their casters 43 are rolling on the peripheries of the two cams. The construction shown in Figure 5 permits the pairs of arms 37 and 38 to thus move in opposite directions and also causes. each pair of arms 37 and 38 to move the other when either of the pairs of arms is moved. The spring 47 always holds the band 48 between each group of pairs of arms in a taut condition, thereby assuring the continuous engagement of the cams by the caster wheels when the shaft 11 is being rotated to start the motor.

This arrangement also keeps the motor in time, but of course, after the motor starts to run by its own power, the action on the compression and explosionpistons will tend to hold, the casters in engagement with the cams and as a matter of fact, it is this action that causes the engine to rotate the shaft 11 for the obtaining of useful power.

The firing order of the combustion cylinders may be varied, but when my invention is of the design shown in the drawings, it is at least recommended that the rear cylinder will fire at the same time that the forward cylinder positioned on the diametrically opposite side of the crank case fires. By the arrangement of the outlines of the two cams 12 and 13, one to the other, such a firing order carried out throughout the motor will result in two impulses given to the engine shaft 11 at points diametrically opposite from each other. This means smooth power, minimum vibration and minimum wear on the shaft 11 and main bearings of the same.

The practical operation of the invention is as follows: As any group, combination, or bank of cylinders desired may be used, we will take for simplicity, the radial groupshown in Figure 2. To start the motor the shaft 11 is rotated, which will cause the casters 43 to be moved outwardly from the shaft 11 by engagement with the rounded projections 17, 18, and 19. This action will cause the free ends of the arms 37 to also move away from the shaft'll. As the pistons 39 and 41 are connected to the arms 37, these members will slide If, when the casters 43 moved into the depressions 14, 15, and 16, the inward movement'of the pistons 41 sucked in a charge of fuel gas through the intake port 25, the outward movement of the pistons 41 when the arms 37 move outwardly will force this charge through the outlet port 28, past the valve 31 and into the passageway 30.

From this passageway the fuel will pass by the valve 32, through the intake port 29 and into the combustion chamber. On the outward stroke of the piston 41, naturally the one-way valve 26 will be closed. By the piston 41 being operatively connected to the arms 37 at a point some dispiston 41 will in its outward sliding movement travel in advance of the piston 39, I have made the link 42 of greater length than the link 40. However, by the piston 39 being operatively connected to the outer ends of the arms 37 it will travel faster and its length of travel will be greater than the length of travel of the piston 41 and when the arms 3'7 have reached their extreme outward swinging movement the pistons 39 and 41 will both be near the upper portions of their respective cylinders at the same time. As the first travel outwardly of the piston 41 will be greatly in advance of the outward travel of the piston 39, the first action as we have seen, will be to force a charge of explosive-mixture into the explosion cylinders from the compression cylinders. Naturally, this charge will be greatly compressed on entering the explosion cylinders and will be additionally compressed by the outward moving piston heads 39. Just at the time the piston 39 reaches its extreme outward reciprocation or just as it starts its inward sliding movement, the charge is ignited by the spark plug 35. The resultant explosion drives the piston 39 and the arms 37 to which it is secured inwardly and toward the engine shaft 11.

Assuming that the caster wheel 43 engaging the projection 17 is thus driven inwardly, the projection 17 will be moved to the right to permit the movement of the caster wheel its inward movement into the depression 14. As soon as the caster wheel 43 has moved or has started to move into the depression 14 the caster wheel 43 will be properly engaging the projection 18 andas soon as an explosion takes place, which should occur at this time in this cylinder group, the caster 43 will be moved into the depression 15. This action will naturally cause the cam 12 to rotate and the remaining cylinder groups will function in the same manner. It should be noted that as soon as the caster 43 moves into the depression 15 the now advanced projection 18 will have rotated to a position to cause the first considered caster 43 to move away from the shaft 11 and force the cylinders 39 and 41 outwardly, as we have herebefore seen.

By having a cam of three depressions and four groups of cylinders, a motor of perfect balance is obtained and dead centers in the motor are. eliminated. As soon as the piston 39 moves inwardly past the exhaust port and pipe 34, the exploded gases may pass therefrom. This port because of its position, is readily closed by the piston 39 as it starts in its outward reciprocation. By such an arrangement, the combustion cylinders 22 and 23 are firedeach time theirpistons are at an outward position and an efficient twocycle motor is obtained. By the pistons 39 being operatively connected to the extreme ends of the pairs of arms 37 and 38 favorable leverage is obtained in exerting force for the rotating of the cams 12 and 13. When the pistons 41 move inwardly to suck a fuel charge into their cylinders the valves 31 and 32 are naturally in a closed condition. This is also true when the explosion takes place in the combustion cylinder adjacent thereto.

By my invention the pistons reciprocate very rapidly relative to the speed of rotation of the shaft 11. As a matter of fact, by the motor illustrated in the drawings, twenty-four explosive impulses are experienced to one complete -revo'- lution of the shaft 11 and each piston 39 will have made three complete reciprocations. By such construction, my motor may be run at excepstart rolling up on the other side of the depression, thereby eliminating the usual hammering action on the engine shaft. Also by my construction desirable uniform leverage is always obtained on the engine shaft 11, as distinguished from the usual crank shaft construction, where the greatest leverage is obtained when the crank arm has moved to a 45-degree angle from and to the combustion cylinder and the piston therein has exerted the greater portion of its energy and has traveled one-half of its movement toward the engine shaft. The favorable leverage of the explosive impulse to the engine shaft will be further appreciated when it is noted that the action r0- tating the engine shaft is that of a compound 1ever. Thisis obtained by the pair of arms hinged at one of their ends and the engaged projection of the cam secured to the rotatable shaft 11, contacting each other by a caster 43 and using the engine shaft and the hinged portions of the pair of arms as the fulcrum points. Also the explosive impulse is first exerted on the free end of the pair of arms which extend a considerable distance beyond the projection contacted by the caster 43, and additional leverage is thus obtained.

It should also be noted that the inward path traversed by the caster 43 will be in an arc with its center in the pivot point of the pair of arms and that this arc cuts a path to the side of the engine shaft, thereby aiding in exerting a pulling action as well as a pushing action to the cams for rotating the engine shaft. If the compression cylinder is so constructed and designed as to provide exceptionally high pressures and deliver the same to the explosion cylinder as to be automatically ignited thereby, a Diesel type motor will be obtained and one made dispense with the spark plugs 35.

The shaft 11 may be caused to rotate in either direction by merely advancing or retarding the ignition. In other words, if the ignition was so retarded that the same would take place, say at the time when the caster 43 was engaging the projection 19 at a position shown in Fig. 2, the cam would be driven to the left and the shaft 11 would also be rotated to the left. Such an obtained result would eliminate the usual reversing transmissions now in common usage with motors only having one direction of rotation.

Some changes may be made in the construction and arrangement of my improved internal combustion engine without departing from the real spirit and purpose of my invention, and it is my intention to cover by my claims any modified forms of structure or use of mechanical equivalents which may be reasonably included within their scope.

I claim: 1. In a-device of the class described, a crank ,case, a shaft rotatably mounted in said crank ends of said arm, and a caster wheel rotatably mounted to said arm designed to engage said cam.-

2. In a device of the class described, a crank case, a shaft rotatably mounted in said crank case, a combustion cylinder and a compression cylinder secured to said crank case, a spark plug threaded into said combustion cylinder for firing the same at times, a one-way means of communication between said compression cylinder and said combustion cylinder, a fuel inlet port in said compression cylinder, an exhaust port in said combustion cylinder, a multifaced cam in said crank case and rigidly secured to said shaft, an arm hinged at one end inside said crank case and extending between said cam and said cylinders, a piston slidably mounted in each of said cylinders, a link connecting the piston in said combustion cylinder with the free end of said arm, a link connecting the piston in said compression cylinder with said arm at a point between the two ends of said arm, and a caster Wheel rotatably mounted to said arm at a point between the two points where said links are secured to said arm; said caster designed to roll on and engage said cam.

3. In a device of the class described, a crank case, a shaft rotatably mounted in said crank case, a combustion cylinder and a compression cylinder secured to said crank case, a spark plug threaded into said combustion cylinder for firing the same at times, a one-way means of communication between said compression cylinder and said combustion cylinder, a fuel inlet port in said compression cylinder, an exhaust port in said combustion cylinder, a multi-faced cam in said crank case and rigidly secured to said shaft, an arm hinged at one end inside said crank case and extending between said cam and said cylinders, a piston slidably mounted in each of said cylinders, a link connecting the piston in said combustion cylinder with the free end of said arm, a link connecting the piston in said compression cylinder with said arm at a point between the two ends of said arm; said link being of greater length than the length of the first mentioned link, and

resigns a caster wheel rotatably mounted to said arm designed to engage said cam.

44. In a device of the class described, a crank case, a shaft rotatably mounted in said crank case, a multi-faced cam in said crank case rigidly secured to said shaft, a second duplicate cam spaced apart from said first mentioned cam inside said crank case and rigidly secured to said shaft; said cams having their faces staggered relative to each other, a cylinder secured to said crank case in line with said first mentioned cam, a second cylinder secured to said crank case and in line with said second mentioned cam, an arm pivotally securedto the inside of said crank case and extending between said first mentioned cam and said first mentioned cylinder, a piston slidably mounted in said first mentioned cylinder, a link operatively connecting said piston to said arm, a caster on said arm capable of engaging said first mentioned cam, a second arm pivotally secured to the inside of said crank case and extending between said second cam and said second cylinder, a piston slidably mounted in said second cylinder, a link for operatively connecting said last mentioned piston with said last mentioned arm, a caster rotatably secured to said second arm capable of engaging said second cam, a spark plug in each of said cylinders for firing the same, an inlet and an outlet port in each of said cylinders, a bolt slidably mounted inside said crank case and positioned between said two arms, a spring for yieldingly holding said bolt to one direction of its sliding movement, a toggle member pivotally secured to said bolt, and 9. flexible band engaging said toggle, having one end operatively secured to one of said arms and its other end operatively secured to the other said arm. 1

5. In a device of the class described, a crank case, a shaft rotatably mounted in said crank case, a cylinder secured to said crank case, a second cylinder secured to said crank case parallel with and in close proximity to said firstmentioned cylinder, a spark plug threaded into one of said cylinders, inlet and outlet openings in each of said cylinders, a. multi-faced cam in said crank case and rigidly secured to said shaft, an arm hinged at one end inside said crank case -and extending between said cam and said cylinders, a piston slidably mounted in each of said cylinders, a link connecting the piston in said first cylinder with the free end of said arm, a link connecting the piston in the second-mentioned cylinder with said arm at a point between the two ends of said arm, and a cam-engaging member operatively secured to said arm and in engagement with said cam.

" ALVIN L. HART. 

